hell for me most of the achievements didn't even cause problems for me. I have only "boosted" with friends for a handful of achievements which was mostly map specific achievements which were rarely played unless you play a special mode, and even then most people went for the "popular" map so it was hard to get it.

Let alone on the note for it have the "worst" achievements you might as well consider any sports games that is either 2 years, or older since the servers are more than likely shut down. You could lump in any shooters, and fighting games that are 2 games behind the newest game release for the franchise, because you'd more than likely have to "boost" for their achievements.